1. Field of the Invention
The present invention relates to an optical/magnetic head actuator, and more particularly, to an ultra-small optical/magnetic head actuator.
2. Description of the Related Art
As information technology grows, data storage devices are being produced with higher densities, and thus have large capacities while small in size. While flash memories have advantages of mobility, durability, and rewritablity, they are relatively expensive and have limited density because of limitations in semiconductor processing. Accordingly, optical/magnetic data storage devices using optical media such as compact disks (CDs) or digital versatile disks (DVDs) or magnetic media such as hard disks are still widely used.
Optical/magnetic data storage devices include an optical/magnetic head for reading or writing information on an optical or magnetic medium, and an optical/magnetic head actuator for driving the optical/magnetic head. An optical head actuator is disclosed in U.S. Pat. No. 6,768,601, entitled “A Position Control Unit for a Lens of an Optical Pickup Device”, issued Jul. 27, 2004, invented by Chae Min Ju, and assigned to LG electronics. This invention controls the position of a lens in a focusing direction and a tracking direction using six wires. However, the invention uses general-purpose magnets for operation in the focusing direction, thereby resulting in an increase in thickness. Accordingly, it is not suitable for an ultra-small optical head actuator for driving an ultra-small optical pickup device.
A magnetic head actuator is disclosed in U.S. Patent Publication No. 2003/0044096, entitled “A Pivot Bearing for a Swing Arm of a Hard Disk Driver”, published on Mar. 6, 2003, invented by Toshisada Koyama, Yasuhiro Mouri, assigned to Minebea Kabushiki-kaisha. This invention uses a pivot bearing to move a swing arm in a tracking direction. However, when the pivot bearing is used to rotate the swing arm, friction or backlash and non-repetitive errors occur due to a bearing clearance.